White Matter Microstructure Associated with the Antidepressant Effects of Deep Brain Stimulation in Treatment-Resistant Depression: A Review of Diffusion Tensor Imaging Studies

Abstract

Treatment-resistant depression (TRD) is a severe disorder characterized by high relapse rates and decreased quality of life. An effective strategy in the management of TRD is deep brain stimulation (DBS), a technique consisting of the implantation of electrodes that receive a stimulation via a pacemaker-like stimulator into specific brain areas, detected through neuroimaging investigations, which include the subgenual cingulate cortex (sgCC), basal ganglia, and forebrain bundles. In this context, to improve our understanding of the mechanism underlying the antidepressant effects of DBS in TRD, we collected the results of diffusion tensor imaging (DTI) studies exploring how WM microstructure is associated with the therapeutic effects of DBS in TRD. A search on PubMed, Web of Science, and Scopus identified 11 investigations assessing WM microstructure in responders and non-responders to DBS. Altered WM microstructure, particularly in the sgCC, medial forebrain bundle, cingulum bundle, forceps minor, and uncinate fasciculus, was associated with the antidepressant effect of DBS in TRD. Overall, the results show that DBS targeting selective brain regions, including the sgCC, forebrain bundle, cingulum bundle, rectus gyrus, anterior limb of the internal capsule, forceps minor, and uncinate fasciculus, seem to be effective for the treatment of TRD.

Multimodal structural neuroimaging data unveil data-driven subtypes of treatment-resistant depression

“…Furthermore, a high-value strength of this work is the clinical validation of the discovered clusters, which can potentially provide insights for new effective treatments tailored on the patient’s biological and clinical profile. For instance, patients assigned to the high-TRD cluster might benefit from antidepressant therapies inducing neuroplastic changes, such as electroconvulsive therapy (70–73), repetitive transcranial magnetic stimulation (74, 75), deep brain stimulation (76, 77), and ketamine (78–80), whereas treatments targeting the immune-metabolic pathways, such as physical exercise, diet or anti-inflammatory treatments, may be also useful in alleviating the energy-related symptoms (81–83). Furthermore, considering that the high-TRD cluster was also associated with high scores for CTQ, this group may benefit from adjunctive psychotherapeutic interventions focused on trauma (84, 85).…”

“…perpetuity. preprint (which was not certified by peer review) is the author/funder, who has granted medRxiv a license to display the preprint in The copyright holder for this this version posted September 18, 2023. ; https://doi.org/10.1101/2023.09.12.23295423 doi: medRxiv preprint 13 neuroplastic changes, such as electroconvulsive therapy (70)(71)(72)(73), repetitive transcranial magnetic stimulation (74,75), deep brain stimulation (76,77), and ketamine (78)(79)(80), whereas treatments targeting the immunemetabolic pathways, such as physical exercise, diet or anti-inflammatory treatments, may be also useful in alleviating the energy-related symptoms (81)(82)(83). Furthermore, considering that the high-TRD cluster was also associated with high scores for CTQ, this group may benefit from adjunctive psychotherapeutic interventions focused on trauma (84,85).…”

Brain asymmetries from mid- to late life and hemispheric brain age

“…Abnormalities in cingulum asymmetry have been linked to schizophrenia [74][75][76] and epilepsy 77,78 , and Alzheimer's disease 59 . Additionally, the cingulum tract was associated with the anti-depressant effects of deep brain stimulation in treatment-resistant depression 79 . Recent evidence points out strongest polygenic risk associations for several psychiatric disorders in addition to Alzheimer's Disease with longitudinal WM in the cerebral peduncle 58 .…”

SmartFSCV: An Artificial Intelligence Enabled Miniaturised FSCV Device Targeting Serotonin

“…Furthermore, SSRIs have been used to treat alcohol use disorder (AUD) [12] , nicotine and other substance use disorders [9] , [13] . Because of the variable clinical efficacy of SSRIs, the long time frame (weeks) for clinical benefits and stagnation in developing improved SSRIs, [14] , the community has turned to other treatments such as ketamine [15] , psychedelics [16] and deep brain stimulation (DBS) [17] , [18] , [19] . However, none of these alternative therapies currently show clinical outcomes that are an improvement on SSRIs.…”